Light-sensitive material comprising light-sensitive layer comprising a salt of a hydrazine derivative with an organic acid provided on support

ABSTRACT

A light-sensitive material comprises a support and a light-sensitive layer, characterized in that the light-sensitive layer contains silver halide, a polymerizable compound containing carbon to carbon unsaturation and a slat of a hydrazine derivative with an acid. An image-forming method utilizing the light-sensitive material is also disclosed.

This is a continuation-in-part of application Ser. No. 024,753, filed3/11/87, now abandoned.

FIELD OF THE INVENTION

This invention relates to a light-sensitive material comprising alight-sensitive layer provided on a support, and an image-forming methodemploying the light-sensitive material.

BACKGROUND OF THE INVENTION

Light-sensitive materials comprising a light-sensitive layer containingsilver halide, a reducing agent and a polymerizable compound provided ona support can be used in an image forming method in which a latent imageof silver halide is formed, and then the polymerizable compound ispolymerized to form the corresponding image.

Examples of said image forming methods are described in Japanese PatentPublication Nos. 45(1970)-11149 (corresponding to U.S. Pat. No.3,697,275), 47(1972)-20741 (corresponding to U.S. Pat. No. 3,687,667)and 49(1974)-10697, and Japanese Patent Provisional Publication Nos.57(1982)-138632, 57(1982)-142638, 57(1982)-176033, 57(1982)-211146(corresponding to U.S. Pat. No. 4,557,997), 58(1983)-107529(corresponding to U.S. Pat. No. 4,560,637),58(1983)-121031(corresponding to U.S. Pat. No. 4,547,450) and58(1983)-169143. In these image forming methods, when the exposed silverhalide is developed using a developing solution, the polymerizablecompound is induced to polymerize in the presence of a reducing agent(which is oxidized) to form a polymer image. Thus, these methods need awet development process employing a developing solution. Therefore theprocess takes a relatively long time.

An improved image forming method employing a dry process is described inJapanese Patent Provisional Publication Nos. 61(1986)-69062 and61(1986)-73145 (the contents of both publications are described in U.S.Pat. No. 4,629,676 and European Patent Provisional Publication No.0174634A2). In this image forming method, a recording material (i.e.,light-sensitive material) comprising a light-sensitive layer containinga light-sensitive silver salt (i.e., silver halide), a reducing agent, across-linkable compound (i.e., polymerizable compound) and a binderprovided on a support is imagewise exposed to form a latent image, andthen the material is heated to polymerize within the area where thelatent image of the silver halide has been formed. The above methodemploying the dry process and the light-sensitive material employablefor such method are also described in Japanese Patent ProvisionalPublications Nos. 61(1986)-183640, 61(1986)-188535 and 61(1986)-228441(the contents of these three publications are described in U.S. patentapplication Ser. No. 827,702).

In the above-mentioned light-sensitive materials, the reducing agent hasa function of reducing the silver halide and/or a function ofaccelerating polymerization of the polymerizable compound. Examples ofthe reducing agents having these functions include hydrazines andconventional photographic developing agents, such as hydroquinones,catechols, p-aminophenols, p-phenylenediamines, 3-pyrazolidones,3-aminopyrazoles, 4-amino-5-pyrazolones, 5-aminouracils,4,5-dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- orp-sulfonamidophenols, o- or p-sulfonamidonaphthols,2-sulfonamidoindanones, 4-sulfonamido-5-pyrazolones,3-sulfonamidoindoles, sulfonamidopyrazolobenzimidazoles,sulfonamidopyrazolotriazoles, α-sulfonamidoketones etc. Among them, ahydrazine derivative is most preferred.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a light-sensitivematerial which is improved particularly in the preservability.

There is provided by the present invention a light-sensitive materialcomprising a support and a light-sensitive layer, characterized in thatthe light-sensitive layer contains silver halide, a polymerizablecompound containing carbon to carbon unsaturation and a salt of ahydrazine derivative with an acid.

The light-sensitive material of the invention can be advantageously usedin a process which comprises:

imagewise exposing the light-sensitive material to form a latent imageof the silver halide, and

heating the light-sensitive material either simultaneously with or afterthe imagewise exposure to release the hydrazine derivative from the saltand to polymerize the polymerizable compound within the area where thelatent image of the silver halide has been formed.

The light-sensitive material of the invention is characterized in thatthe light-sensitive layer contains the hydrazine derivative in the formof a salt.

The present inventor has found that the above-mentioned reducing agentstend to affect the preservability of the other component in thelight-sensitive layer or to be decomposed by itself under certainpreservative conditions. The present inventor has further found that ahydrazine derivative (which is most preferred as the reducing agent) hasthe most remarkable tendency to be decomposed among the reducing agent.

According to study of the present inventor, a salt of the hydrazinederivative is much stable, and the hydrazine derivative can be releasedfrom the salt in a development process. The light-sensitive material ofthe invention is improved in the preservability, since the hydrazinederivative is preserved in the form of the salt. Therefore, thelight-sensitive material of the invention can give a clear image, evenif the light-sensitive material is preserved for a long term or under asevere condition, because the functions of the light-sensitive materialwith respect to the maximum density, the minimum density, thesensitivity and the gradation of the obtained image can be stablymaintained under the conditions.

DETAILED DESCRIPTION OF THE INVENTION

There is no specific limitation with respect to the hydrazinederivative.

Examples of the hydrazine derivative include various compounds, such as1-acetyl-2-phenylhydrazine, 1-acetyl-2-(p- or o-aminophenyl)hydrazine,1-formyl-2-(p- or o-aminophenyl)hydrazine, 1-acetyl-2-(p- oro-methoxyphenyl)hydrazine, 1-lauroyl-2-(p- or o-aminophenyl)hydrazine,1-trityl-2-(2,6-dichloro-4-cyanophenyl)hydrazine,1-trityl-2-phenylhydrazine, 1-phenyl-2-(2,4,6-trichlorophenyl)hydrazine,1,-{2-(2,5-di-tert-pentylphenoxy)butyloyl}-2-(p- oro-aminophenyl)hydrazine, 1-{2-(2,5-di-t-pentylphenoxy)butyloyl}-2-(p- oro-aminophenyl)hydrazine pentadecylfluorocaprylate salt, 3-indazolinone,1-(3,5-dichlorobenzoyl)-2-phenylhydrazine,1-trityl-2-[{(2-N-butyl-N-octylsulfamoyl)-4-methanesulfonyl}phenyl]hydrazine,1-{4-(2,5-di-tert-pentylphenoxy)butyloyl}-2-(p- oro-methoxyphenyl)hydrazine,1-(methoxycarbonylbenzohydryl)-2-phenylhydrazine,1-formyl-2-[4-{2-(2,4-di-tert-pentylphenoxy)butylamide}phenyl]hydrazine,1-acetyl-2-[4-{2-(2,4-di-tert-pentylphenoxy)butylamido}phenyl]hydrazine,1-trityl-2-[{2,6-dichloro-4-(N,N-di-2-ethylhexyl)carbamoyl}phenyl]hydrazine,1-(methoxycarbonylbenzohydryl)-2-(2,4-dichlorophenyl)hydrazine and1-trityl-2-[{2-(N-ethyl-N-octylsulfamoyl)-4-methanesulfonyl}phenyl]hydrazine.

Among them, a hydrazine derivative having the formula (I) is mostpreferred, since it is excellent in various functions except forpreservability. ##STR1##

In the formula (I), R¹ is a monovalent group selected from the groupconsisting of an alkyl group (preferably containing 1-20 carbon atoms),a cycloalkyl group (preferably containing 5-10 carbon atoms), an aralkylgroup (preferably containing 7-20 carbon atoms), an aryl group(preferably containing 6-20 carbon atoms), an alkenyl group (preferablycontaining 2-20 carbon atoms), an alkynyl group (preferably containing2-20 carbon atoms) and a heterocyclic group, each of which may have oneor more substituent groups. An aryl group, an aralkyl group and aheterocyclic group are more preferred. An aryl group is most preferred.

As for R¹, examples of the alkyl group include methyl, ethyl, n-butyl,hexyl, 2-ethylhexyl, decyl, undecyl, dodecyl, hexadecyl, octadecyl,2-methoxyethyl, 2-chloroethyl and furfuryl. Examples of the cycloalkylgroup include cyclopentyl and cyclohexyl. Examples of the aralkyl groupinclude diphenylmethyl, benzyl, 9-fluorenyl and 1-phenylethyl. Examplesof the aryl group include phenyl, tolyl, xylyl, aminophenyl(p-aminophenyl is particularly preferred), methoxyphenyl,dimethoxyphenyl, 2-methoxy-4-methylphenyl, naphthyl and2-methoxynaphthyl. Examples of the alkenyl group include propenyl,butenyl and styryl. Examples of the alkynyl group include propargyl andphenylethynyl. Examples of the heterocyclic group include4-ethoxyphthalazino, pyridyl, imidazolyl and indolyl.

In the formula (I), R² is a monovalent group selected from the groupconsisting of hydrogen, an alkyl group (preferably containing 1-20carbon atoms), a cycloalkyl group (preferably containing 5-10 carbonatoms), an aralkyl group (preferably containing 7-20 carbon atoms), anaryl group (preferably containing 6-20 carbon atoms), an alkenyl group(preferably containing 2-20 carbon atoms), an alkynyl group (preferablycontaining 2-20 carbon atoms), a heterocyclic group, an alkoxy group(preferably containing 1-20 carbon atoms), an aryloxy group (preferablycontaining 6-20 carbon atoms), an alkylthio group (preferably containing1-20 carbon atoms), an arylthio group (preferably containing 6-20 carbonatoms) and amino, each of which (except hydrogen) may have one or moresubstituent groups. An alkyl group, an aralkyl group, an aryl group, analkenyl group, an alkynyl group and a heteroxyclic group are morepreferred.

As for R², examples of the alkyl group include methyl, trifluoromethyl,trichloromethyl, t-butyl, heptyl, pentadecafluoroheptyl and3-(2,4-t-pentylphenoxy)propyl. An examples of the cycloalkyl group iscyclohexyl. Examples of the aralkyl group include benzyl anddiphenylmethyl. Examples of the aryl group include phenyl,dichlorophenyl, methoxycarbonylphenyl, tolyl, 4-cyanophenyl andnaphthyl. Examples of the alkenyl group include styryl, propenyl andbutenyl. Examples of the SO alkynyl group include phenylethynyl andpropargyl. Examples of the heterocyclic group include pyridyl,benzimidazolyl, quinolyl, thienyl, furyl, benzothiazolyl andbenzochromanyl. Examples of the alkoxy group include trifluoroethoxy and2-methoxyethoxy. Examples of the aryloxy group include phenoxy and4-cyanophenoxy. Examples of the alkylthio group include n-butylthio,n-octylthio and dodecylthio. An examples of the arylthio group isphenylthio. Examples of the substituted amino group includediethylamino, dibutylamino, benzylamino and di-2-ethylhexylamino.

Examples of the hydrazine derivative having the formula (I) are shownbelow. ##STR2##

The light-sensitive material of the invention employs theabove-mentioned hydrazine derivative in the form of a salt.

Examples of the acid which is preferably used in the salt includesulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, sulfonicacid, sulfenic acid, sulfamic acid, sulfuric ester, phosphonic acid,carboxylic acid, hydroxamic acid, strongly acidic phenol, phosphoricester, pyrubic acid, organic boric acid and a polymer compound of theseacids. Organic acids are preferred to inorganic acids.

Examples of the acid which are preferably used in the salt are describedhereinafter. ##STR3##

Examples of the salt comprising the hydrazine derivative and the acidare described hereinafter. ##STR4##

These salts of the hydrazine derivative can be used singly or incombination. The amount of the salts of the hydrazine derivative in thelight-sensitive layer preferably ranges from 0.1 to 1,500 mole % basedon the amount of silver (contained in silver halide and an organicsilver salt).

The salt of the hydrazine derivative is preferably used in combinationwith a developing agent.

Examples of the developing agent include hydroquinones, catechols,p-aminophenols, p-phenylenediamines, 3-pyrazolidones, 3-aminopyrazoles,4-amino-5-pyrazolones, 5-aminouracils, 4,5-dihydroxy-6-aminopyrimidines,reductones, aminoreductones, o- or p-sulfonamidophenols, o- orp-sulfonamidonaphthols, 2-sulfonamidoindanones,4-sulfonamido-5-pyrazolones, 3-sulfonamidoindoles,sulfonamidopyrazolobenzimidazoles, sulfonamidopyrazolotriazoles andα-sulfonamidoketones. Concrete examples of the developing agent includepentadecylhydroquinone, 5-t-butylcatechol, p-(N,N-diethylamino)phenol,1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone,1-phenyl-4-methyl-4-heptadecylcarbonyloxymethyl-3-pyrazolidone,2-phenylsulfonylamino-4-hexadecyloxy-5-t-octylphenol,2-phenylsulfonylamino-4-t-butyl-5-hexadecyloxyphenol,2-(N-butylcarbamoyl)-4-phenylsulfonylaminonaphtol and2-(N-methyl-N-octadecylcarbamoyl)-4-sulfonylaminonaphthol.

In the case that the hydrazine derivative is used in combination withthe developing agent, certain interactions between the hydrazinederivative and the developing agent may be expected. One of theinteractions is for acceleration of reduction of silver halide (and/oran organic silver salt) through so-called superadditivity. Otherinteraction is for a chain reaction in which an oxidized state of thedeveloping agent formed by a reduction of silver halide (and/or anorganic silver salt) induces the polymerization of the polymerizablecompound via oxidation-reduction reaction with the hydrazine derivative.Both interactions may occur simultaneously. Thus, it is difficult todetermine which of the interactions has occurred in practical use.

The developing agents having these functions are described in T. James,"The Theory of the Photographic Process", 4th edition, 291-334 (1977),Research Disclosure No. 17029, 9-15 (June 1978), and Research DisclosureNo. 17643, 22-31 (December 1978).

The amount of the developing agent in the light-sensitive layerpreferably ranges from 0.1 to 1,500 mole % based on the amount of silver(contained in silver halide and an organic silver salt).

The developing agent may be contained in the light-sensitive layer inthe form of a salt similarly to the hydrazine derivative. Examples ofthe salt comprising the developing agent and an acid are describedhereinafter. ##STR5##

The above-mentioned salts generally release the hydrazine derivative (ordeveloping agent) when it is in contact with an activator or when it isheated. The salt which can release a hydrazine derivative upon heatingrequires no activator and treatment to release the hydrazine derivativein the case that a heat development is utilized for developing thelight-sensitive material.

In the case that the salt releases a hydrazine derivative (or developingagent) when it is in contact with an activator, the development processshould be done in presence of the activator. For example, in adevelopment process employing a developing solution, the activator ofthe salt can be previously contained in the developing solution.Alternatively, in the case that a heat development process is utilizedfor developing the light-sensitive material, the light-sensitivematerial preferably comprising a light-sensitive layer in which thesilver halide, the salt of the hydrazine derivative and thepolymerizable compound are contained in microcapsules which aredispersed in the light-sensitive layer, and the activator is arrangedoutside of the microcapsules. The activator arranged outside of themicrocapsules can permeate the microcapsule in the heat developmentprocess.

Example of the activater of the salt is a base or a base precursor whichcan release a base in the development process.

Preferred examples of the inorganic bases include hydroxides of alkalimetals or alkaline earth metals; secondary or tertiary phosphates,borates, carbonates, quinolinates and metaborates of alkali metals oralkaline earth metals; a combination of zinc hydroxide or zinc oxide anda chelating agent (e.g., sodium picolinate); ammonium hydroxide;hydroxides of quaternary alkylammoniums; and hydroxides of other metals.Preferred examples of the organic bases include aliphatic amines (e.g.,trialkylamines, hydroxylamines and aliphatic polyamines); aromaticamines (e.g., N-alkyl-substituted aromatic amines,N-hydroxylalkyl-substituted aromatic amines andbis[p-(dialkylamino)phenyl]-methanes), heterocyclic amines, amidines,cyclic amidines, guanidines, and cyclic guanidines. Of these bases,those having a pKa of 7 or more are preferred.

The base precursors preferably are those capable of releasing bases uponreaction by heating, such as salts between bases and organic acidscapable of decarboxylation by heating, compounds capable of releasingamines through intramolecular nucleophilic substitution, Lossenrearrangement, or Beckmann rearrangement, and the like; and thosecapable of releasing bases by electrolysis. Preferred examples of thebase precursors include guanidine trichloroacetate, piperidinetrichloroacetate, morpholine trichloroacetate, p-toluidinetrichloroacetate, 2-picoline trichloroacetate, guanidinephenylsulfonylacetate, guanidine 4-chlorophenylsulfonylacetate,guanidine 4-methyl-sulfonylphenylsulfonylacetate, and4-acetylaminomethyl propionate.

These bases or base precursors are preferably used as an activator ofthe precursor in an amount of not more than 50% by weight, and morepreferably from 0.1 to 40% by weight, based on the total solid contentof the light-sensitive layer. These bases or base precursors can be usedsingly or in combination.

An antioxidant for the salt of the hydrazine derivative can be used incombination with the salt. Examples of the antioxidant are knowncompounds in the conventional art of photography, such as sodiumsulfite, hydroxyl amine and sodium ascorbate.

The silver halide, the polymerizable compound and the support whichconstitute the light-sensitive material of the invention with the saltof the hydrazine derivative are described below. Thus composed materialis referred hereinafter to as "light-sensitive material".

There is no specific limitation with respect to silver halide containedin the light-sensitive layer of the light-sensitive material.

Examples of the silver halides include as silver chloride, silverbromide, silver iodide, silver chlorobromide, silver chloroiodide,silver iodobromide, and silver chloroiodobromide in the form of grains.

The halogen composition of individual grains may be homogeneous orheterogeneous. The heterogeneous grains having a multilayered structurein which the halogen composition varies from the core to the outer shell(see Japanese Patent Provisional Publication Nos. 57(1982)-154232,58(1983)-108533, 59(1984)-48755 and 59(1984)-52237, U.S. Pat. No.4,433,048, and European Patent No. 100,984) can be employed.

There is no specific limitation on the crystal habit of silver halidegrains. Two or more kinds of silver halide grains which differ inhalogen composition, crystal habit, grain size, and/or other featuresfrom each other can be used in combination. There is no specificlimitation on grain size distribution of silver halide grains. Thesilver halide grains ordinarily have a mean size of 0.001 to 5 μm, morepreferably 0.001 to 2 μm.

The total silver content (including the silver halide and an organicsilver salt which is one of optional components) in the light-sensitivelayer preferably is in the range of from 0.1 mg/m² to 10 g/m². Thesilver content of the silver halide in the light-sensitive layerpreferably is not more than 0.1 g/m², more preferably in the range offrom 1 mg to 90 mg/m².

There is no specific limitation with respect to the polymerizablecompound, except that the compound contains carbon to carbonunsaturation. In the case that heat development (i.e., thermaldevelopment) is utilized for developing the light-sensitive material,the polymerizable compounds having a relatively higher boiling point(e.g., 80° C. or higher) that are hardly evaporated upon heating arepreferably employed. In the case that the light-sensitive layer containsa color image forming substance, the polymerizable compounds arepreferably cross-linkable compounds having plural polymerizable groupsin the molecule, because such cross-linkable compounds favorably servefor fixing the color image forming substance in the course ofpolymerization hardening of the polymerizable compounds.

Preferred examples of the polymerizable compounds containing carbon tocarbon unsaturation include compounds having an ethylenic unsaturatedgroup.

Examples of compounds having an ethylenic unsaturated group includeacrylic acid, salts of acrylic acid, acrylic esters, acrylamides,methacrylic acid, salts of methacrylic acid, methacrylic esters,methacrylamide, maleic anhydride, maleic esters, itaconic esters,styrene, styrene derivatives, vinyl ethers, vinyl esters, N-vinylheterocyclic compounds, allyl ethers, allyl esters, and compoundscarrying a group or groups corresponding to one or more of thesecompounds.

Concrete examples of the acrylic esters include n-butyl acrylate,cyclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, furfurylacrylate, ethoxyethoxy acrylate, dicyclohexyloxyethyl acrylate,nonylphenyloxyethyl acrylate, hexanediol diacrylate, butanedioldiacrylate, neopentylglycol diacrylate, trimethylolpropane triacrylate,pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate,diacrylate of polyoxyethylenated bisphenol A, polyacrylate ofhydroxypolyether, polyester acrylate, and polyurethane acrylate.

Concrete examples of the methacrylic esters include methyl methacrylate,butyl methacrylate, ethylene glycol dimethacrylate, butanedioldimethacrylate, neopentylglycol dimethacrylate, trimethylolpropanetrimethacrylate, pentaerythritol trimethacrylate, pentaerythritoltetramethacrylate, and dimethacrylate of polyoxyalkylenated bisphenol A.

The polymerizable compounds can be used singly or in combination of twoor more compounds. Further, compounds formed by bonding a polymerizablegroup such as a vinyl group or a vinylidene group to a salt of thehydrazine derivative or a color image forming substance are alsoemployed as the polymerizable compounds. The light-sensitive materialsemploying these compounds which show functions as both the salt of thehydrazine derivative and the polymerizable compound, or of the colorimage forming substance and the polymerizable compound are included inembodiments of the invention.

The amount of the polymerizable compound for incorporation into thelight-sensitive layer preferably ranges from 5 to 1.2×10⁵ times (byweight) as much as the amount of silver halide, more preferably from 10to 1×10⁴ times as much as the silver halide.

The light-sensitive material of the invention can be prepared byarranging a light-sensitive layer containing the above-mentionedcomponents on a support. There is no limitation with respect to thesupport. In the case that heat development is utilized in the use of thelight-sensitive material, the material of the support preferably isresistant to heat given in the processing stage. Examples of thematerial employable for the preparation of the support include glass,paper, fine paper, coat paper, synthetic paper, metals and analoguesthereof, polyester, acetyl cellulose, cellulose ester, polyvinyl acetal,polystyrene, polycarbonate, polyethylene terephthalate, and paperlaminated with resin or polymer (e.g., polyethylene).

Various embodiments of the light-sensitive materials, optionalcomponents which may be contained in the light-sensitive layer, andauxiliary layers which may be optionally arranged on the light-sensitivematerials are described below.

The polymerizable compound is preferably dispersed in the form of oildroplets in the light-sensitive layer. Other components in thelight-sensitive layer, such as silver halide, the salt of the hydrazinederivative, the color image forming substances may be also contained inthe oil droplets.

The oil droplets of the polymerizable compound are preferably preparedin the form of microcapsules. There is no specific limitation onpreparation of the microcapsules. There is also no specific limitationon shell material of the microcapsule, and various known materials suchas polymers which are employed in the conventional microcapsules can beemployed as the shell material. The mean size of the microcapsulepreferably ranges from 0.5 to 50 μm, more preferably 1 to 25 μm, mostpreferably 3 to 20 μm.

At least 70% of the silver halide is preferably arranged in the shell ofthe microcapsule. More preferably, at least 90% of the silver halide isarranged in the shell.

The light-sensitive layer can further contain optional components suchas color image forming substances, sensitizing dyes, organic silversalts, various kinds of image formation accelerators, thermalpolymerization inhibitors, thermal polymerization initiators,development stopping agents, fluorescent brightening agents,discoloration inhibitors, antihalation dyes or pigments, antiirradiationdyes or pigments, matting agents, antismudging agents, plasticizers,water releasers and binders.

There is no specific limitation with respect to the color image formingsubstance, and various kinds of substances can be employed. Thus,examples of the color image forming substance include both coloredsubstance (i.e., dyes and pigments) and non-colored or almostnon-colored substance (i.e., color former or dye- or pigment-precursor)which develops to give a color under application of external energy(e.g., heating, pressing, light irradiation, etc.) or by contact withother components (i.e., developer). The light-sensitive material usingthe color image forming substance is described in Japanese PatentProvisional Publication No. 61(1986)-73145.

Examples of the dyes and pigments (i.e., colored substances) employablein the invention include commercially available ones, as well as variousknown compounds described in the technical publications, e.g., YukiGosei Kagaku Kyokai (ed.), Handbook of Dyes (in Japanese, 1970) andNippon Ganryo Gijutsu Kyokai (ed.), New Handbook of Pigments (inJapanese, 1977). These dyes and pigments can be used in the form of asolution or a dispersion.

Examples of the substances which develop to give a color by certainenergy includes thermochromic compounds, piezochromic compounds,photochromic compounds and leuco compounds derived from triarylmethanedyes, quinone dyes, indigoid dyes, azine dyes, etc. These compounds arecapable of developing a color by heating, application of pressure,light-irradiation or air-oxidation.

Examples of the substances which develop to give a color in contact withother components include various compounds capable of developing a colorthrough some reaction between two or more components, such as acidbasereaction, oxidation-reduction reaction, coupling reaction, chelatingreaction, and the like. Examples of such color formation systems aredescribed in Hiroyuki Moriga, "Introduction of Chemistry of SpecialityPaper" (in Japanese, 1975), 29-58 (pressure-sensitive copying paper).87-95 (azo-graphy), 118-120(heat-sensitive color formation by a chemicalchange) or in MSS. of the seminer promoted by the Society of KinkiChemical Industry, "The Newest Chemistry of Coloring Matter--AttractiveApplication and New Development as a Functional Coloring Matter", 26-32(June, 19, 1980). Examples of the color formation systems specificallyinclude a color formation system used in pressure-sensitive papers,etc., comprising a color former having a partial structure of lactone,lactam, spiropyran, etc., and an acidic substance (developer), e.g.,acid clay, phenol, etc.; a system utilizing azo-coupling reactionbetween an aromatic a diazonium salt, diazotate or diazosulfonate andnaphthol, aniline, active methylene, etc.; a system utilizing achelating reaction, such as a reaction between hexamethylenetetramineand a ferric ion and gallic acid, or a reaction between aphenolphthalein-complexon and an alkaline earth metal ion; a systemutilizing oxidation-reduction reaction, such as a reaction betweenferric stearate and pyrogallol, or a reaction between silver behenateand 4-methoxy-1-naphthol, etc.

The color image forming substance in the light-sensitive material ispreferably used in an amount of from 0.5 to 50 parts by weight, and morepreferably from 2 to 30 parts by weight, per 100 parts by weight of thepolymerizable compound. In the case that the developer is used, it ispreferably used in an amount of from about 0.3 to about 80 parts byweight per one part by weight of the color former.

There is no specific limitation with respect to the sensitizing dyes,and known sensitizing dyes used in the conventional art of photographymay be employed in the light-sensitive material of the invention.Examples of the sensitizing dyes include methine dyes, cyanine dyes,merocyanine dyes, complex cyanine dyes, complex merocyanine dyes,holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonoldyes. These sensitizing dyes can be used singly or in combination.Combinations of sensitizing dyes are often used for the purpose ofsuper-sensitization. In addition to the sensitizing dyes, a substancewhich does not per se exhibit spectral sensitization effect or does notsubstantially absorb visible light but shows supersensitizing activitycan be used. The amount of the sensitizing dye to be added generallyranges from about 10⁻⁸ to about 10⁻² mol per 1 mol of silver halide. Thesensitizing dye is preferably added during the stage of the preparationof the silver halide emulsion.

When the heat development is employed in the use of the light-sensitivematerial, an organic silver salt is preferably contained in thelight-sensitive material. It can be assumed that the organic silver salttakes part in a redox reaction using a silver halide latent image as acatalyst when heated to a temperature of 80° C. or higher. In such case,the silver halide and the organic silver salt preferably are located incontact with each other or close together. Examples of organic compoundsemployable for forming such organic silver salt include aliphatic oraromatic carboxylic acids, thiocarbonyl group-containing compoundshaving a mercapto group or an α-hydrogen atom, imino group-containingcompounds, and the like. Among them, benzotriazoles are most preferable.The organic silver salt is preferably used in an amount of from 0.01to10 mol., and preferably from 0.01to 1 mol., per 1 mol. of thelight-sensitive silver halide. Instead of the organic silver salt, anorganic compound (e.g., benzotriazole) which can form an organic silversalt in combination with an inoganic silver salt can be added to thelight-sensitive layer to obtain the same effect.

Various image formation accelerators are employable in thelight-sensitive material of the invention. The image formationaccelerators have a function to accelerate the oxidation-reductionreaction between a silver halide (and/or an organic silver salt) and areducing agent, a function to accelerate emigration of an image formingsubstance from a light-sensitive layer to an image-receiving material oran image-receiving layer, or a similar function. The image formationaccelerators can be classified into inoragnic bases, organic bases, baseprecursors (these bases and base precursors are above mentioned), oils,surface active agents, hot-melt solvents, and the like. These groups,however, generally have certain combined functions, i.e., two or more ofthe above-mentioned effects. Thus, the above classification is for thesake of convenience, and one compound often has a plurality of functionscombined.

Various examples of these image formation accelerators are shown below.

Examples of the oils employable in the invention include high-boilingorganic solvents which are used as solvents in emulsifying anddispersing hydrophobic compounds.

Examples of the surface active agents employable in the inventioninclude pyridinium salts, ammonium salts and phosphonium salts asdescribed in Japanese Patent Provisional Publication No. 59(1984)-74547;polyalkylene oxides as described in Japanese Patent ProvisionalPublication No. 59(1984)-57231.

The hot-melt solvents preferably are compounds which may be used assolvent of the reducing agent or those which have high dielectricconstant and can accelerate physical development of silver salts.Examples of the hot-melt solvents include polyethylene glycols,derivatives of polyethylene oxides (e.g., oleate ester), beeswax,monostearin and high dielectric constant compounds having --SO₂ --and/or --CO-- group described in U.S. Pat. No. 3,347,675: polarcompounds described in U.S. Pat. No. 3,667,959; and 1,10-decanediol,methyl anisate and biphenyl suberate described in Research Disclosure26-28 (December 1976). The light-sensitive material employing thehot-melt solvents is described in Japanese Patent Application No.60(1985)-227527. The hot-melt solvent is preferably used in an amount offrom 0.5 to 50% by weight, and more preferably from 1 to 20% by weight,based on the total solid content of the light-sensitive layer.

The thermal polymerization initiators employable in the light-sensitivematerial preferably are compounds that are decomposed under heating togenerate a polymerization initiating species, particularly a radical,and those commonly employed as initiators of radical polymerization. Thethermal polymerization initiators are described in "AdditionPolymerization and Ring Opening Polymerization", 6-18. edited by theEditorial Committee of High Polymer Experimental Study of the HighPolymer Institute, published by Kyoritsu Shuppan (1983). Examples of thethermal polymerization initiators include azo compounds, e.g.,azobisisobutyronitrile, 1,1'-azobis(1-cyclohexanecarbonitrile), dimethyl2,2'-azobisisobutyrate, 2,2'-azobis(2-methylbutyronitrile), andazobisdimethylvaleronitrile; organic peroxides, e.g., benzoyl peroxide,di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, andcumene hydroperoxide; inorganic peroxides, e.g., hydrogen peroxide,potassium persulfate, and ammonium persulfate; and sodiump-toluenesulfinate. The thermal polymerization initiators are preferablyused in an amount of from 0.1 to 120% by weight, and more preferablyfrom 1 to 10% by weight, based on amount of the polymerizable compound.The light-sensitive material employing the thermal polymerizationinitiators is described in Japanese Patent Provisional Publication No.61(1986)-260241.

The development stopping agents employable in the light-sensitivematerial are compounds that neutralize a base or react with a base toreduce the base concentration in the layer to thereby stop development,or compounds that mutually react with silver or a silver salt tosuppress development. More specifically, examples of the developmentstopping agents include acid precursors capable of releasing acids uponheating electrophilic compounds capable of undergoing substitutionreaction with a coexisting base upon heating, nitrogen-containingheterocyclic compounds, mercapto compounds, and the like. Examples ofthe acid precursors include oxide esters described in Japanese PatentProvisional Publication Nos. 60(1985)-108837 and 60(1985)-192939 andcompounds which release acids through Lossen rearrangement described inJapanese Patent Provisional Publication No. 60(1985)-230133. Examples ofthe electrophilic compounds which induce substitution reaction withbases upon heating are described in Japanese Patent ProvisionalPublication No. 60(1985)-230134.

The antismudging agents employable in the light-sensitive materialpreferably are particles which are solid at ambient temperatures.Examples of the antismudging agents include starch particles describedin U.K. Patent No. 1,232,347; polymer particles described in U.S. Pat.No. 3,625,736; microcapsule particles containing no color formerdescribed in U.K. Patent No. 1,235,991; and cellulose particles, andinorganic particles, such as particles of talc, kaolin, bentonite,agalmatolite, zinc oxide, titanium dioxide or aluminum oxide describedin U.S. Pat. No. 2,711,375. Such particles preferably have a mean sizeof 3 to 50 μm, more preferably 5 to 40 μm. When the microcapsule isemployed in the light-sensitive material, the size of said particle ispreferably larger than that of the microcapsule.

Binders employable in the light-sensitive material preferably aretransparent or semi-transparent hydrophilic binders. Examples of thebinders include natural substances, such as gelatin, gelatinderivatives, cellulose derivatives, starch, and gum arabic; andsynthetic polymeric substances, such as water-soluble polyvinylcompounds e.g., polyvinyl alcohol, polyvinylpyrrolidone, and acrylamidepolymers. In addition to the synthetic polymeric substances, vinylcompounds dispersed in the form of latex, which are particularlyeffective to increase dimensional stability of photographic materials,can be also used. These binders can be used singly or in combination.The light-sensitive material employing a binder is described in JapanesePatent Provisional Publication No. 61(1986)-69062.

Examples and usage of the other optional components which can becontained in the light-sensitive layer are also described in theabove-mentioned publications and applications concerning thelight-sensitive material, and in Research Disclosure Vol. 170, No.17029, 9-15 (June 1978).

Examples of auxiliary layers which are optionally arranged on thelight-sensitive material include an image-receiving layer, a heatinglayer, an antistatic layer, an anticurl layer and a release layer.

Instead of the use of the image-receiving material, the image-receivinglayer can be arranged on the light-sensitive material to produce thedesired image on the on the image-receiving layer of the light-sensitivematerial. The image-receiving layer of the light-sensitive material canbe constructed in the same manner as the layer of the image-receivingmaterial. The details of the image-receiving layer will be describedlater.

The light-sensitive material employing the heating layer is described inJapanese Patent Application No. 60(1985)-135568 (corresponding toEuropean Patent Provisional Publication No. 203613A). Examples and usageof the other auxiliary layers are also described in the above-mentionedpublications and applications concerning the light-sensitive material.

The light-sensitive material of the invention can be prepared forinstance, by the following process.

The light-sensitive material is usually prepared by dissolving,emulsifying or dispersing each of the components of the light-sensitivelayer in an adequate medium to obtain coating solution, and then coatingthe obtained coating solution on a support.

The coating solution can be prepared by mixing liquid compositions eachcontaining a component of the light-sensitive layer. Liquid compositioncontaining two or more components may be also used in the preparation ofthe coating solution. Some components of the light-sensitive layer canbe directly added to the coating solution or the liquid composition.Further, a secondary composition can be prepared by emulsifying the oily(or aqueous) composition in an aqueous (or oily) medium to obtain thecoating solution.

The silver halide is preferably prepared in the form of a silver halideemulsion. Various processes for the preparation of the silver halideemulsion are known in the conventional technology for the preparation ofphotographic materials.

The silver halide emulsion can be prepared by the acid process, neutralprocess or ammonia process. In the stage for the preparation, a solublesilver salt and a halogen salt can be reacted in accordance with thesingle jet process, double jet process or a combination thereof. Areverse mixing method, in which grains are formed in the presence ofexcess silver ions, or a controlled double jet process, in which a pAgvalue is maintained constant, can be also employed. In order toaccelerate grain growth, the concentrations or amounts or the silversalt and halogen salt to be added or the rate of their addition can beincreased as described in Japanese Patent Provisional Publication Nos.55(1980)-142329and 55(1980)-158124, and U.S. Pat. No. 3,650,757, etc.

The silver halide emulsion may be of a surface latent image type thatforms a latent image predominantly on the surface of silver halidegrains, or of an inner latent image type that forms a latent imagepredominantly in the interior of the grains. A direct reversal emulsioncomprising an inner latent image type emulsion and a nucleating agentmay be employed. The inner latent image type emulsion suitable for thispurpose is described in U.S. Pat. Nos. 2,592,250 and 3,761,276, JapanesePatent Publication No. 58(1983)-3534 and Japanese Patent ProvisionalPublication No. 57(1982)-136641, etc. The nucleating agent that ispreferably used in combination with the inner latent image type emulsionis described in U.S. Pat. Nos. 3,227,552, 4,245,037, 4,255,511,4,266,013 and 4,276,364, and West German Patent Provisional Publication(OLS) No. 2,635,316.

In the preparation of the silver halide emulsions, hydrophilic colloidsare advantageously used as protective colloids. Examples of usablehydrophilic colloids include proteins, e.g., gelatin, gelatinderivatives, gelatin grafted with other polymers, albumin, and casein;cellulose derivatives, e.g., hydroxyethyl cellulose, carboxymethylcellulose, cellulose sulfate, etc.; saccharide derivatives, e.g., sodiumalginate and starch derivatives; and a wide variety of synthetichydrophilic polymers, such as polyvinyl alcohol, polyvinyl alcoholpartial acetal, poly-N-vinylpyrrolidone, polyacrylic acid,polymethacrylic acid, polyacrylamide, polyvinylimidazole, andpolyvinylpyrazole, and copolymers comprising monomers constituting thesehomopolymers. Among them, gelatin is most preferred. Examples ofemployable gelatins include not only lime-processed gelatin, but alsoacid-processed gelatin and enzyme-processed gelatin. Hydrolysis productsor enzymatic decomposition products of gelatin can also be used.

In the formation of silver halide grains in the silver halide emulsion,ammonia, an organic thioether derivative as described in Japanese PatentPublication No. 47(1972)-11386 or sulfur-containing compound asdescribed in Japanese Patent Provisional Publication No. 53(1978)-144319can be used as a silver halide solvent. Further, in the grain formationor physical ripening, a cadmium salt, a zinc salt, a lead salt, athallium salt, or the like can be introduced into the reaction system.Furthermore, for the purpose of improving high or low intensityreciprocity law failure, a water-soluble iridium salt, e.g., iridium(III) or (IV) chloride, or ammonium hexachloroiridate, or awater-soluble rhodium salt, e.g., rhodium chloride can be used.

After the grain formation or physical ripening, soluble salts may beremoved from the resulting emulsion by a known noodle washing method ora sedimentation method. The silver halide emulsion may be used in theprimitive condition, but is usually subjected to chemical sensitization.Chemical sensitization can be carried out by the sulfur sensitization,reduction sensitization or noble metal sensitization, or a combinationthereof that are known for emulsions for the preparation of theconventional light-sensitive materials.

When the sensitizing dyes are added to the silver halide emulsion, thesensitizing dye is preferably added during the preparation of theemulsion. When the organic silver salts are introduced in thelight-sensitive microcapsule, the emulsion of the organic silver saltscan be prepared in the same manner as in the preparation of the silverhalide emulsion.

In preparation of the light-sensitive material, the polymerizablecompounds are used as the medium for preparation of the liquidcomposition containing another component of the light-sensitive layer.For example, the silver halide, including the silver halide emulsion),the salt of the hydrazine derivative, or the color image formingsubstance can be dissolved, emulsified or dispersed in the polymerizablecompound to prepare the light-sensitive material. Especially, the colorimage forming substance is preferably incorporated in the polymerizablecompound. Further, the necessary components for preparation of amicrocapsule, such as shell material can be incorporated into thepolymerizable compound.

The light-sensitive composition which is the polymerizable compoundcontaining the silver halide can be prepared using the silver halideemulsion. The light-sensitive composition can be also prepared usingsilver halide powders which can be prepared by lyophilization. Theselight-sensitive composition can be obtained by stirring thepolymerizable compound and the silver halide using a homogenizer, ablender, a mixer or other conventional stirring device.

Polymers having a principal chain consisting essentially of ahydrocarbon chain substituted in part with hydrophilic groups whichcontain, in their terminal groups, --OH or nitrogen having a loneelectron-pair are preferably introduced into the polymerizable compoundprior to the preparation of the light-sensitive composition. The polymerhas a function of dispersing silver halide or other component in thepolymerizable compound very uniformly as well as a function of keepingthus dispered state. Further, the polymer has another function ofgathering silver halide along the interface between the polymerizablecompound (i.e., light-sensitive composition) and the aqueous medium inpreparation of the microcapsule. Therefore, using this polymer, silverhalide can be easily introduced into the shell material of themicrocapsule.

The polymerizable compound (including the light-aqueous sensitivecomposition) are preferably emulsified in an aqueous medium to preparethe coating solution. The necessary components for preparation of themicrocapsule, such as shell material can be incorporated into theemulsion. Further, other components such as the salt of the hydrazinederivative can be added to the emulsion.

The emulsion of the polymerizable compound can be processed for formingshell of the microcapsule. Examples of the process for the preparationof the microcapsules include a process utilizing coacervation ofhydrophilic wall-forming materials as described in U.S. Pat. Nos.2,800,457 and 2,800,458; an interfacial polymerization process asdescribed in U.S. Pat. No. 3,287,154, U.K. Patent No. 990,443 andJapanese Patent Publication Nos. 38(1963)-19574, 42(1967)-446 and42(1967)-771; a process utilizing precipitation of polymers as describedin U.S. Pat. Nos. 3,418,250 and 3,660,304; a process of usingisocyanate-polyol wall materials as described in U.S. Pat. No.3,796,669; a process of using isocyanate wall materials as described inU.S. Pat. No. 3,914,511; a process of using urea-formaldehyde orurea-formaldehyde-resorcinol wall-forming materials as described in U.S.Pat. Nos. 4,001,140, 4,087,376 and 4,089,802; a process of usingmelamineformaldehyde resins hydroxypropyl cellulose or like wall-formingmaterials as described in U.S. Pat. No. 4,025,455; an in situ processutilizing polymerization of monomers as described in U.K. Patent No.867,797 and U.S. Pat. No. 4,001,140; an electrolytic dispersion andcooling process as described in U.K. Patent Nos. 952,807 and 965,074; aspray-drying process as described in U.S. Pat. No. 3,111,407 and U.K.Patent 930,422; and the like. It is preferable, though not limitative,that the microcapsule is prepared by emulsifying core materialscontaining the polymerizable compound and forming a polymeric membrane(i.e., shell) over the core materials.

When the emulsion of the polymerizable compound (including thedispersion of the microcapsule) has been prepared by using thelight-sensitive composition, the emulsion can be used as the coatingsolution of the light-sensitive material. The coating solution can bealso prepared by mixing the emulsion of the polymerizable compound andthe silver halide emulsion.

The salt of the hydrazine derivative is preferably incorporated into thepolymerizable compound (including the light-sensitive composition) toprepare the light-sensitive material of the invention. The salt of thehydrazine derivative can be directly added to the polymerizablecompound, or dispersed in an adequate medium (e.g., methylene chloride)prior to the addition to the polymerizable compound.

Alternatively, the salt of the hydrazine derivative can be incorporatedinto the emulsion of the polymerizable compound or the coating solutionto prepare the light-sensitive material of the invention.

A light-sensitive material of the invention can be prepared by coatingand drying the above-prepared coating solution on a support in theconventional manner.

Use of the light-sensitive material is described below.

In the use of the light-sensitive material of the invention, adevelopment process is conducted simultaneously with or after animagewise exposure.

Various exposure means can be employed in the image-wise exposure, andin general, the latent image on the silver halide is obtained byimagewise exposure to radiation including visible light. The type oflight source and exposure can be selected depending on thelight-sensitive wavelengths determined by spectral sensitization orsensitivity of silver halide. Original image can be either monochromaticimage or color image.

Development of the light-sensitive material can be conductedsimultaneously with or after the imagewise exposure. The development canbe conducted using a developing solution in the same manner as the imageforming method described in Japanese Patent Publication No.45(1970)-11149. The image forming method described in Japanese PatentProvisional Publication No. 61(1986)-69062 which employs a heatdevelopment process has an advantage of simple procedures and shortprocessing time because of the dry process. Thus, the latter method ispreferred as the development process of the light-sensitive material.

Heating in the heat development process can be conducted in variousknown manners. The heating layer which is arranged on thelight-sensitive material can be used as the heating means. Heatingtemperatures for the development process usually ranges from 80° C. to200° C., and preferably from 100° C. to 160° C. Various heating patternsare applicable. The heating time is usually from 1 second to 5 minutes,and preferably from 5 seconds to 1 minute.

In the above development process, a polymer image can be formed on thelight-sensitive layer. A pigment image can be also obtained by fixingpigments to the polymer image.

The image can be also formed on the image-receiving material. Theimage-receiving material is described hereinbelow. The image formingmethod employing the image-receiving material or the image-receivinglayer is described in Japanese Patent Provisional Publication No.61(1986)-278849.

Examples of the material employable as the support of theimage-receiving material include baryta paper in addition to variousexamples which can be employed as the support of the knownlight-sensitive material.

The image-receiving material is usually prepared by providing theimage-receiving layer on the support. The image-receiving layer can beconstructed according to the color formation system. In the cases that apolymer image is formed on the image-receiving material and that a dyeor pigment is employed as the color image forming substance, theimage-receiving material be composed of a simple support.

For example, when a color formation system using a color former anddeveloper is employed, the developer can be contained in theimage-receiving layer. Further, the image-receiving layer can becomposed of at least one layer containing a mordant. The mordant can beselected from the compounds known in the art of the conventionalphotography according to the kind of the color image forming substance.If desired, the image-receiving layer can be composed of two or morelayers containing two or more mordants different in the mordanting powerfrom each other.

The image-receiving layer preferably contains a polymer as binder. Thebinder which may be employed in the above-mentioned light-receivinglayer is also employable in the image-receiving layer.

The image-receiving layer can be composed of two or more layersaccording to the above-mentioned functions. The thickness of theimage-receiving layer preferably ranges from 1 to 100 μm, morepreferably from 1 to 20 μm.

After the development process, pressing the light-sensitive material incontact with the image-receiving material to transfer the unpolymerizedpolymerizable compound to the image-receiving material, a polymer imagecan be obtained in the image-receiving material. The process forpressing can be carried out in various known manners.

In the case that the light-sensitive layer contains a color imageforming substance, the color image forming substance is fixed bypolymerization of the polymerizable compound. Then, pressing thelight-sensitive material in contact with the image-receiving material totransfer the color image forming substance in unfixed portion, a colorimage can be produced on the image-receiving material.

The light-sensitive material can be used for monochromatic or colorphotography, printing, radiography, diagnosis (e.g., CRT photography ofdiagnostic device using supersonic wave), copy (e.g., computer-graphichard copy), etc.

The present invention is further described by the following exampleswithout limiting the invention.

EXAMPLE 1 Preparation of silver halide emulsion

In 1,000 ml of water were dissolved 20 g of gelatin and 3 g of sodiumchloride, and the resulting gelatin solution was kept at 75° C. To thegelatin solution, 600 ml of an aqueous solution containing 21 g ofsodium chloride and 56 g of potassium bromide and 600 ml of an aqueoussolution containing 0.59 mole of silver nitrate were addedsimultaneously at the same feed rate over a period of 40 minutes toobtain a silver chlorobromide emulsion having cubic grains, uniformgrain size distribution, a mean grain size of 0.35 μm and a bromidecontent of 80 mole %.

The emulsion was washed for desalting and then subjected to chemicalsensitization with 5 mg of sodium thiosulfate and 20 mg of4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene at 60° C. to obtain thesilver halide emulsion. The yield of the emulsion was 600 g.

Preparation of silver benzotriazole emulsion

In 3,000 ml of water were dissolved 28 g of gelatin and 13.2 g ofbenzotriazole, and the solution was kept at 40° C. while stirring. Tothe solution was added 100 ml of an aqueous solution of 17 g of silvernitrate over 2 min. An excessive salt were sedimented by pH-adjustmentand removed from the resulting emulsion. Thereafter, the emulsion waadjusted to pH 6.30 to obtain a silver benzotriazole emulsion. The yieldof the emulsion was 400 g.

Preparation of light-sensitive composition

In 100 g of pentaerythritol tetraacrylate were dissolved 0.40 g of thefollowing copolymer, 6.00 g of Pargascript Red I-6-B (tradename,Ciba-Geigy) and 2 g of Emulex NP-8 (tradename, preduced by NipponEmulsion Co., Ltd.). ##STR6##

In 18.0 g of the resulting solution was dissolved 0.002 g of thefollowing thiol derivative. To the solution was added a solution inwhich 0.18 g of the following salt of the hydrazine derivative(H-44.A-25) was dissolved in 1.80 g of methylene chloride. ##STR7##

Further, to the resulting solution were added 3.50 of the silver halideemulsion and 3.35 g of the silver benzotriazole emulsion, and themixture was stirred at 15,000 r.p.m. for 5 min. using a homogenizer toobtain a light-sensitive composition.

Preparation of light-sensitive microcapsule

To 10.51 g of 18.6% aqueous solution of Isobam (tradename, produced byKuraray Co., Ltd.) was added 48.56% of 2.89% aqueous solution of pectin.After the solution was adjusted to a pH of 4.0 using 10% sulfuric acid,the light-sensitive composition was added to the resulting solution, andthe mixture was stirred at 7,000 r.p.m. for 2 min. to emulsify thelight-sensitive composition in the aqueous medium.

To 72.5 g of the aqueous emulsion were added 8.32 g of 40% aqueoussolution of urea, 2.82 g of 11.3% aqueous solution of resorcinol, 8.56 gof 37% aqueous solution of formaldehyde, and 2.74 g of 8.76% aqueoussolution of ammonium sulfate in this order, and the mixture was heatedat 60° C. for 2 hours while stirring. After the mixture was adjusted toa pH of 7.0 using 10% aqueous solution of sodium hydroxide, 3.62 g of30.9% aqueous solution of sodium hydrogen sulfite was added to themixture to obtain a dispersion containing light-sensitive microcapsules.

Preparation of light-sensitive material

To 10.0 g of the light-sensitive microcapsule dispersion were added 1.0g of 10% aqueous solution of the following anionic surfactant and 1.0 gof 10% solution (solvent: water/ethanol=50/50 volume ratio) of guanidinetrichroloacetate to prepare a coating solution. ##STR8##

The coating solution was uniformly coated on a polyethyleneterephthalate film (thickness: 100 μm) using a coating rod of #40 togive a layer having a wet thickness of 70 μm and dried at about 40° C.to obtain a light-sensitive material (A).

COMPARISON EXAMPLE 1 Preparation of light-sensitive material

Light-sensitive material (B) was prepared in the same manner as inExample 1 except that 0.08 g of the following hydrazine derivative(H-44) was used in place of 0.18 g of the salt of the hydrazinederivative (H-44.A-25). ##STR9##

Preparation of image-receiving material

To 125 g of water was added 11 g of 40% aqueous solution of sodiumhexametaphosphate, and were further added 34 g of zinc3,5-di-α-methylbenzylsalicylate and 82 g of 55% aqueous slurry ofcalcium carbonate, followed by coarsely dispersing in a mixer. Thecoarse dispersion was then finely dispersed in Dynomill dispersingdevice. To 200 g of the resulting dispersion were added 6 g of 50% latexof SBR (styrene-butadiene rubber) and 55 g of 8% aqueous solution ofpolyvinyl alcohol, and the resulting mixture was made uniform.

The mixture was then uniformly coated on an art paper having a basisweight of 43 g/m² to give a layer having a wet thickness of 30 μm anddried to obtain an image-receiving material.

Evaluation of light-sensitive material

Each of the light-sensitive materials prepared in Example 1 andComparison Example 1 was imagewise exposed to light using a tungstenlamp at 200 lux for 1 second and then heated on a hot plate at 125° C.for 40 seconds. Each of the exposed and heated light-sensitive materialswas then combined with the image-receiving material and passed throughpress rolls under pressure of 350 kg/cm² to obtain a magenta positiveimage on the image receiving material. The maximum density (unexposedarea) and the minimum density (exposed area) of the obtained image weremeasured using Macbeth reflection densitometer. The ratio (R) of themaximum density (Dmax) to the minimum density (Dmin) was obtainedaccording to the following formula.

    R=Dmax/Dmin

Further, each of the light-sensitive materials prepared in Example 1 andComparison Example 1 was contained in a thermostat at 50° C. for 1 day,and then processed as mentioned above. The maximum density and theminimum density of the obtained image were measured using Macbethreflection densitometer, and the ratio (R) was obtained as mentionedabove.

The results are set forth in Table 1. In Table 1, "R⁰ " means the ratio(R) obtained immediately after the preparation of the light-sensitivematerial, and "R¹ " means the ratio (R) obtained after thelight-sensitive material was contained in the thermostat at 50° C. for 1day.

                  TABLE 1                                                         ______________________________________                                        Light-    Hydrazine                                                           sensitive Derivative or                                                       Material  Salt thereof                                                                             R.sup.0   R.sup.1                                                                           R.sup.1 /R.sup.0                           ______________________________________                                        (A)       (H-44.A-25)                                                                              5.2       4.0 0.77                                       (B)       (H-44)     7.0       1.2 0.17                                       ______________________________________                                    

It is apparent from the results in Table 1 that the light-sensitivematerial using a salt of the hydrazine derivative is improved in thepreservability.

EXAMPLE 2 Preparation of silver halide emulsion

In 3 l of water were dissolved 40 g of gelatin and 23.8 g of potassiumbromide, and the resulting gelatin solution was kept at 50° C. To thegelatin solution, 200 ml of an aqueous solution containing 34 g ofsilver nitrate was added over a period of 10 minutes while stirring. Tothe solution, 100 ml of an aqueous solution containing 3.3 g ofpotassium iodide was added over a period of 2 minutes to obtain a silverbromoiodide emulsion. After the emulsion was adjusted to a pH forsedimentation, excess salts were removed, and the emulsion was adjustedto a pH of 6.0. The yield of the emulsion was 400 g.

Preparation of light-sensitive composition

In 100 g of trimethylolpropane triacrylate were dissolved 0.40 g of thecopolymer used in Example 1 and 6.00 g of Pargascript Red I-6-B(tradename, Chiba-Geigy). To 18.00 g of the resulting solution was addeda mixture which is prepared by mixing 4.06 g of the above silver halideemulsion and 0.6 ml of 0.04% methanol solution of following dye andstirred for 5 minutes. The resulting mixture was stirred at 15,000r.p.m. for 5 min. to obtain a light-sensitive composition. ##STR10##

Preparation of light-sensitive microcapsule

Dispersion of light-sensitive microcapsule was prepared in the samemanner as in Example 1 except that the above light-sensitive compositionwas used.

Preparation of light-sensitive material

To 10.0 g of the light-sensitive microcapsule dispersion were added 1.0g of 1% aqueous solution of the anionic surfactant used in Example 1,1.0 g of 10% solution (solvent: water/ethanol=50/50 volume ratio) ofguanidine trichroloacetate and a solution (dispersion in part) in which0.13 g of the following salt of the hydrazine derivative (H-43.A-8) wasdissolved in 3 ml of methanol to prepare a coating solution. ##STR11##

The coating solution was uniformly coated on a polyethyleneterephthalate film (thickness: 100 μm) using a coating rod of #40 togive a layer having a wet thickness of 70 μm and dried at about 25° C.to obtain a light-sensitive material (C).

EXAMPLE 3 Preparation of light-sensitive material

Light-sensitive materials (D) to (F) were prepared in the same manner asin Example 2 except that each of the following salts of the hydrazinederivatives (H-45.A-19), (H-43.A-20) and (H-43.A-23) were respectivelyused in place of 0.13 g of the salt of the hydrazine derivative(H-43.A-8). ##STR12##

COMPARISON EXAMPLE 2 Preparation of light-sensitive material

Light-sensitive materials (I) and (J) were prepared in the same manneras in Example 2 except that the following hydrazine derivatives (H-43)and (H-45) were respectively used in place of 0.13 g of the salt of thehydrazine derivative (H-43.A-8). ##STR13##

Evaluation of light-sensitive material

Each of the light-sensitive materials prepared in Examples 2 & 3 andComparison Example 2 was imagewise exposed to light through a greenfilter which transmits a light having a wavelength from 500 to 600 nmand in which the density continuously changed, using a tungsten lamp at2,000 lux for 1 second and then heated on a hot plate at 125° C. for or40 seconds. Each of the exposed and heated light-sensitive materials wasthen combined with the image-receiving material and passed through pressrolls under pressure of 350 kg/cm² to obtain a magenta positive image onthe image receiving material. The maximum density (unexposed area) andthe minimum density (exposed area) of the obtained image were measuredusing Macbeth reflection densitometer. The ratio (R) of the maximumdensity (Dmax) to the minimum density (Dmin) was obtained according tothe following formula.

    R=Dmax/Dmin

Further, each of the light-sensitive materials prepared in Examples 2 &3 and Comparison Example 2 was contained in a thermostat at 50° C. for 1day, and then processed as mentioned above. The maximum density and theminimum density of the obtained image were measured using Macbethreflection densitometer, and the ratio (R) was obtained as mentionedabove.

The results are set forth in Table 2. In Table 2, "R⁰ " means the ratio(R) obtained immediately after the preparation of the light-sensitivematerial, and "R¹ " means the ratio (R) obtained after thelight-sensitive material was contained in the thermostat at 50° C. for 1day.

                  TABLE 2                                                         ______________________________________                                        Light-    Hydrazine                                                           sensitive Derivative or                                                       Material  Salt thereof                                                                             R.sup.0   R.sup.1                                                                           R.sup.1 /R.sup.0                           ______________________________________                                        (C)       (H-43.A-8) 4.5       3.4 0.76                                       (D)       (H-45.A-19)                                                                              5.2       3.7 0.71                                       (E)       (H-43.A-20)                                                                              4.3       3.3 0.77                                       (F)       (H-43.A-23)                                                                              4.2       3.3 0.79                                       (I)       (H-43)     4.0       0.8 0.20                                       (J)       (H-45)     4.7       0.8 0.17                                       ______________________________________                                    

It is apparent from the results in Table 2 that the light-sensitivematerial using a salt of the hydrazine derivative is improved in thepreservability.

EXAMPLE 4 Preparation of light-sensitive material

A light-sensitive material (M) was prepared in the same manner as inExample 2 except that 0.12 g of the following salt of the hydrazinederivative (H-19.A-8) and 0.13 g of the following salt of the developingagent (D-1.A-8) were used in place of 0.13 g of the salt of thehydrazine derivative (H-43.A-8). ##STR14##

EXAMPLE 5 Preparation of light-sensitive material

A light-sensitive material (N) was prepared in the same manner as inExample 2 except that 0.12 g of the salt of the hydrazine derivative(H-19.A-8 used in Example 4) and 0.05 g of the following salt of thedeveloping agent (D-4.A-24) were used in place of 0.13 g of the salt ofthe hydrazine derivative (H-43.A-8). ##STR15##

COMPARISON EXAMPLE 3 Preparation of light-sensitive material

A light-sensitive material (G) was prepared in the same manner as inExample 2 except that 0.04 g of the following hydrazine derivative(H-19) and 0.13 g of the salt of the developing agent (D-1.A-8 used inExample 4) were used in place of 0.13 g of the salt of the hydrazinederivative (H-43.A-8). ##STR16##

COMPARISON EXAMPLE 4 Preparation of light-sensitive material

A light-sensitive material (H) was prepared in the same manner as inExample 2 except that 0.04 g of the hydrazine derivative (H-19 used inComparison Example 3) and 0.05 g of the salt of the developing agent(D-4.A-24 used in Example 5) were used in place of 0.13 g of the salt ofthe hydrazine derivative (H-43.A-8).

COMPARISON EXAMPLE 5 Preparation of light-sensitive material

A light-sensitive material (K) was prepared in the same manner as inExample 2 except that 0.04 g of the hydrazine derivative (H-19 used inComparison Example 3) and 0.05 g of the following developing agent (D-1)were used in place of 0.13 g of the salt of the hydrazine derivative(H-43.A-8). ##STR17##

COMPARISON EXAMPLE 6 Preparation of light-sensitive material

A light-sensitive material (L) was prepared in the same manner as inExample 2 except that 0.04 g of the hydrazine derivative (H-19 used inComparison Example 3) and 0.04 g of the following developing agent (D-4)were used in place of 0.13 g of the salt of the hydrazine derivative(H-43.A-8). ##STR18##

Evaluation of light-sensitive material

Each of the light-sensitive materials prepared in Examples 4 & 5 andComparison Examples 3-6 was evaluated in the same manner as in Examples2 & 3 and Comparison Example 2.

The results are set forth in Table 3. In Table 3, "R⁰ " means the ratio(R) obtained immediately after the preparation of the light-sensitivematerial, and "R¹ " means the ratio (R) obtained after thelight-sensitive material was contained in the thermostat at 50° C. for 1day.

                  TABLE 3                                                         ______________________________________                                        Light- Hydrazine    Developing                                                sensitive                                                                            Derivative or                                                                              Agent or                                                  Material                                                                             Salt thereof Salt thereof                                                                            R.sup.0                                                                             R.sup.1                                                                           R.sup.1 /R.sup.0                      ______________________________________                                        (M)    (H-19.A-8)   (D-1.A-8) 3.9   3.5 0.90                                  (N)    (H-19.A-8)   (D-4.A-24)                                                                              3.5   3.1 0.89                                  (G)    (H-19)       (D-1.A-8) 3.9   3.1 0.79                                  (H)    (H-19)       (D-4.A-24)                                                                              3.3   2.6 0.79                                  (K)    (H-19)       (D-1)     3.8   0.7 0.18                                  (L)    (H-19)       (D-4)     3.0   0.5 0.17                                  ______________________________________                                    

It is apparent from the results in Table 3 that the light-sensitivematerial using a salt of the hydrazine derivative is improved in thepreservability.

I claim:
 1. In a light-sensitive material comprising a support and alight-sensitive layer, the improvement wherein the light-sensitive layercontains silver halide, an ethylenically unsaturated polymerizablecompound, a base or a base precursor, and a salt of a hydrazinederivative with an organic acid, said acid being selected from the groupconsisting of ##STR19##
 2. The light-sensitive material as claimed inclaim 1, wherein the hydrazine derivative has the following formula (I):##STR20## in which R¹ is a monovalent group selected from the groupconsisting of an alkyl group, a cycloalkyl group, an aralkyl group, anaryl group, an alkenyl group, an alkynyl group and a heterocyclic group,each of which may have one or more substituent groups; and R² is amonovalent group selected from the group consisting of hydrogen, analkyl group, a cycloalkyl group, an aralkyl group, an aryl group, analkenyl group, an alkynyl group, a heterocyclic group, an alkoxy group,an aryloxy group, an alkylthio group, an arylthio group and an aminogroup, each of which may have one or more substituent groups.
 3. Thelight-sensitive material as claimed in claim 1, wherein the salt iscontained in an amount of from 0.1 to 1,500 mole % based on the totalsilver content in the light-sensitive layer.
 4. The light-sensitivematerial as claimed in claim 1, wherein the light-sensitive layerfurther contains a developing agent.
 5. The light-sensitive material asclaimed in claim 1, wherein the light-sensitive layer further contains asalt of a developing agent with an acid.
 6. The light-sensitive materialas claimed in claim 1, wherein the light-sensitive layer furthercontains a color image forming substance.
 7. The light-sensitivematerial as claimed in claim 1, wherein the polymerizable compound isdispersed in the light-sensitive layer in the form of oil droplets, andthe silver halide and the salt are contained in the oil droplets.
 8. Thelight-sensitive material as claimed in claim 1, wherein thepolymerizable compound is contained in microcapsules which are dispersedin the light-sensitive layer, the silver halide and the salt arecontained in the microcapsules, and the base or base precursor isarranged outside of the microcapsules.